This paper will present a series of arguments for increased and sustained funding for the F-35 Lightning II Joint Strike Fighter. Beyond question, the program is the key index of weapons modernization for US forces for at least the coming decade, so much so that it will also be a reliable indicator of America’s commitment to maintain global military preeminence. There are many positive reasons why this is so—the sheer size of the F-35 fleet would make it the centerpiece of any large-scale conventional air campaign; its reconnaissance and strike capabilities and ability to act as a “node” in a larger “network” of joint systems make it much more than a stealthy tactical aircraft; and its durability and ease of maintenance will create a capacity for large-scale, “everyday” stealth.

But there are also other, less happy reasons why the F-35 is so necessary. These have less to do with the qualities of the Lightning II and more to do with the unavoidable fact that there is no real alternative. The challenges of building the F-35 are partly a consequence of the sheer complexity of the system, but even more so the government’s chaotic management of the program, and, most of all, irregular funding.

The challenges faced by the F-35 project can be understood in the context of a larger failure to modernize—much less to “transform”—the capabilities of US military forces. In sum, there is no modernization alternative other than stretching a few more miles and flying hours out of legacy aircraft of increasingly limited value. Fortunately, the Lighting II is an extremely capable plane. But no technology remains forever on the cutting edge; maximizing the value of the F-35 investment demands quick fielding and higher rates of production.

In this paper, we will make four broad arguments for why the F-35 is the right solution:

Building Partner Capacity (BPC). BPC has become a Pentagon cure for many ailments, and in the context of the George W. Bush administration’s 2006 Quadrennial Defense Review Report, BPC meant expanding and upgrading Iraqi and Afghan security forces and indigenous allies in irregular war. But the principle probably holds greater strategic benefit when applied to the new conventional challenges of the coming era: responding to China’s military modernization, the need to maintain a convincing conventional deterrent (or “compellent”) against a potentially nuclear-armed Iran, and the need to jumpstart a deeper and wide-ranging defense relationship with India. Thus, the F-35—always structured as an international program—would be the centerpiece of three strategic coalitions: in East Asia, the Persian Gulf, and South Asia and the Indian Ocean.

Anti-Access and Area Denial (A2/AD). The A2/AD problem—which now has an even deeper grip on Pentagon imaginations than does BPC—is a product of Chinese military modernization, but one that is also reflected in Iran and elsewhere. The rest of the world was mightily impressed by US power-projection capabilities during the wars of the post-Soviet era, and the rest of the world is gradually finding—principally in the form of massive fleets of cheap and accurate ballistic and cruise missiles—ways to hold in-theater US forces at risk. The “accuracy revolution,” until now the sole property of the United States, is rapidly going global.

For most observers, the solution lies first of all in longer-range systems. While long-range weapons are increasingly worth the premium they demand, simply responding to the A2/AD phenomenon as an operational problem is a fool’s errand. Direct operational responses must be supplemented—indeed dictated by—a larger and more strategic approach that combines mass with range, and sustainability with rapid reaction. These are capabilities that, for the foreseeable future, reside exclusively with the F-35.

The Future of the US Marine Corps. After being entrenched in Iraq, Afghanistan, and irregular warfare missions since 9/11, the Marine Corps is now rightly reconsidering what unique role it can and should play in overall US defense posture. At the same time, the renewal of the Corps’ sea-based capabilities has suffered: not only was the faster, longer-range Expeditionary Fighting Vehicle program terminated (a decision almost certainly resulting in the expensive kicking of the can down the road), but the short-take-off, vertical-landing “B” model of the F-35 has been on programmatic “probation,” and is a favorite target of Pentagon budget cutters and alleged defense reformers.

If the Marine Corps is to remain relevant—not just in the Indo-Pacific, where such sea-based forces are uniquely valuable—in less-than-benign battlefield circumstances, the Corps requires the firepower and other virtues of the F-35. In many scenarios, Marine amphibious ships with the F-35 may be more useful than a large-deck US Navy carrier with F/A-18 Hornets. Conversely, without the jump-jet F-35, Marine operational concept will be incomplete and still expensive.

The Overall Need for Military Modernization. The F-35—as an industrial-scale realization of the “fifth generation” of aircraft and other systems envisioned near the end of the Cold War and immediately after—was always intended to be the largest project of its era. It is now one of the few remaining opportunities to bring those technologies into use. Early-generation stealth aircraft like the F-117 Nighthawk and B-2 Spirit have passed their primes (and, of course, at 21 bombers, the B-2 fleet was tiny), and the Lighting II’s partner, the F-22 Raptor, was terminated after 187 planes were procured, rather than the 750-plus that were anticipated.

The Army has failed to acquire a major new system, and the Navy’s record for submarines, surface combatants, and advanced aircraft is nearly as dismal. Hundreds of billions of dollars were spent (albeit not fast enough) for one-off systems like the Mine-Resistant Ambush Protected trucks, low-end remotely piloted vehicles, body armor, and other short-term procurements in the post–9/11 wars; these were necessities, but not the foundation for the forces of the future. If the F-35 program is further truncated—indeed, if it is not accelerated and sustained—the United States will essentially have skipped a generation of military modernization.

Thomas Donnelly is the codirector of the Marilyn Ware Center for Security Studies at AEI, where Phillip Lohaus is a research fellow.